Structures of the I-, II- and H-Methane Clathrates and the Ice−Methane Clathrate Phase Transition from Quantum-Chemical Modeling with Force-Field Thermal Corrections
2011 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 115, no 23, 6169-6176 p.Article in journal (Refereed) Published
Methane hydrates with the three clathrate structures I, II and H are studied by quantumchemicalmethods. The periodic B3LYP computations are combined with force-field methodsfor the thermal energy corrections. The pressure dependencies for the crystal structures, latticeenergies and guest molecule interactions are derived. Quantum-chemical geometryoptimizations predict too small cell volumes compared to experimental data, but includingzero-point energy and thermal energy the cell volume increases and the correct densities areobtained. Phase diagram for the three structures are investigated, and phase transitions werefound at 5 GPa for the MH-I–MH-II transition and at 10 GPa for the MH-II–MH-H transition.
Place, publisher, year, edition, pages
ACS Publications , 2011. Vol. 115, no 23, 6169-6176 p.
IdentifiersURN: urn:nbn:se:liu:diva-53177DOI: 10.1021/jp111328vOAI: oai:DiVA.org:liu-53177DiVA: diva2:287416
The original title of this article was: "Structure and phase transitions of I-, II- and H- methane clathrates and ice from quantum-chemical B3LYP computations with corrections for thermal effects".2010-01-182010-01-182015-03-09Bibliographically approved